Tohoku Electric Power Co. said the tsunami that struck northern Japan on March 11 reached as high as 13 meters (43 feet) at its Onagawa nuclear station, almost a meter below the site’s base.
The tsunami didn’t reach major buildings of the plant, which sits on a base about 13.8 meters higher than sea level, it said in a statement on its website. While the company found some traces of seawater at the site, there was no significant damage to the power station.
Peak seismic accelerations from the magnitude-9 quake exceeded design limits at several locations of the plant, it said. Tohoku Electric confirmed functions of nuclear reactor buildings have been maintained and will conduct further inspections, it said. It didn’t give a timetable for restarting the reactors.
Tohoku Electric’s calculations are based on a preliminary report by the Geospatial Information Authority of Japan, which estimates that the site sunk about 1 meter because of changes in the earth’s crust, the utility said.
The three reactors at the plant in Miyagi prefecture were safely shut after the earthquake and cooling systems continued to operate.
About 120 kilometers (74 miles) down the coast, Tokyo Electric Power Co. has been trying to cool down reactors at its Fukushima Dai-Ichi plant after the quake and tsunami knocked out the station’s cooling systems, causing radiation to leak in the world’s worst nuclear accident since Chernobyl.